A semiconductor device known in the art includes a wiring substrate and electronic components mounted on the wiring substrate. Each electronic component emits electromagnetic waves in accordance with its operation. Also, the electronic component may be affected by electromagnetic waves received from the exterior. In this regard, some semiconductor devices may include a shield case that prevents emission of electromagnetic waves from the electronic components mounted on the wiring substrate and entrance of electromagnetic waves into the electronic components. Japanese laid-open patent publication No. 2006-173493 describes one example of a semiconductor device that includes a shield case.